| Abstract: | Regional blood flow and capillary permeability in the experimental brain tumors and their surrounding brain tissue of rats were measured with quantitative 14C-antipyrine and 14C-alpha-aminoisobutyric acid (AIB) autoradiographic method. The pharmacokinetic implications with respect to drug delivery to tumor tissue and the effect of ionizing irradiation were discussed in these physiological measurement. A suspension of 1 X 10(4) rat glioma cells (E239 RG 12) was stereotactically implanted into the right basal ganglia of CD-Fisher rats, and spherical brain tumors developed 10-17 days after implantation with a diameter of 1--5 mm. Autoradiographic investigations were performed for rats with small tumors (1--2 mm in diameter) and large tumors (4--5 mm in diameter). The uniform blood flow (91.7 +/- 13.1 ml/100 g/min: mean +/- S.E.) was observed in small tumors with the patchy low flow area (56.7 +/- 12.5 ml/100 g/min) surrounding the tumor. In large tumors, the blood flow was markedly decreased in the central part of the tumor (28.3 +/- 2.4 ml/100 g/min) with a ring shaped high flow area in the peripheral part (59.3 +/- 5.9 ml/100 mg/min). The blood flow in the brain adjacent to the tumor (30.5 +/- 2.5 ml/100 g/min) was lower than that in the peripheral part of the tumor. The uptake of 14C-AIB was quite similar to that of 14C-antipyrine suggesting the smaller permeability in the central part of the tumor. Neuropathological studies did not reveal necrotic foci, but viable cells in these areas.(ABSTRACT TRUNCATED AT 250 WORDS) |
